论文标题
RXCJ1230.7+3439的动态状态：多鞋结构合并星系群
The dynamical state of RXCJ1230.7+3439: a multi-substructured merging galaxy cluster
论文作者
论文摘要
我们使用93种新的光谱红移在36M TNG望远镜和SDSS DR16公共数据中分析了Galaxy群集RXCJ1230.7+3439的运动学和动力学状态，z = 0.332。我们发现RXCJ1230在红移空间中显示为明显孤立的峰，其全局视线速度分散$ 1004 _ { - 122}^{+147} $ km s $ s $ s $ s $^{ - 1} $，并显示出非常复杂的结构，并具有三个子群落。我们的分析证实，所检测到的三个子结构处于合并前阶段，主要相互作用与西南亚倾斜发生。我们计算$σ_\ textrm {v} \ sim 1000 $和$σ_\ textrm {v} \ sim 800 $ km s $^{ - 1} $的速度分散剂分别分别用于主集群和西南子结构。中央主体和西南子结构在LOS速度中的$ \ sim 870 $ km s $^{ - 1} $不同。 From these data, we estimate a dynamical mass of $M_{200}= 9.0 \pm 1.5 \times 10^{14}$ M$_{\odot}$ and $4.4 \pm 3.3 \times 10^{14}$ M$_{\odot}$ for the RXCJ1230 main body and south-west clump, respectively, which reveals that the cluster will suffer a合并为2：1质量比影响。我们解决了这种互动的两体问题，发现最可能的解决方案表明，合并轴几乎包含在天空平面中，并且子集群将在$ \ sim0.3 $ gyr中完全相互作用。动力质量与从X射线数据得出的质量之间的比较表明，在错误（差异$ \ sim 15 $ \％）中达成了良好的一致性，这表明银河系的最内部区域（$ <r_ {500} $）几乎在固定性平衡中。总而言之，RXCJ1230是一个年轻但也大量的集群，在预合并阶段，从其环境中认可其他星系系统。
We analyse the kinematical and dynamical state of the galaxy cluster RXCJ1230.7+3439, at z=0.332, using 93 new spectroscopic redshifts of galaxies acquired at the 3.6m TNG telescope and from SDSS DR16 public data. We find that RXCJ1230 appears as a clearly isolated peak in the redshift space, with a global line-of-sight velocity dispersion of $1004_{-122}^{+147}$ km s$^{-1}$, and showing a very complex structure with the presence of three subclusters. Our analyses confirm that the three substructures detected are in a pre-merger phase, where the main interaction takes place with the south-west subclump. We compute a velocity dispersion of $σ_\textrm{v} \sim 1000$ and $σ_\textrm{v} \sim 800$ km s$^{-1}$ for the main cluster and the south-west substructure, respectively. The central main body and south-west substructure differ by $\sim 870$ km s$^{-1}$ in the LOS velocity. From these data, we estimate a dynamical mass of $M_{200}= 9.0 \pm 1.5 \times 10^{14}$ M$_{\odot}$ and $4.4 \pm 3.3 \times 10^{14}$ M$_{\odot}$ for the RXCJ1230 main body and south-west clump, respectively, which reveals that the cluster will suffer a merging characterized by a 2:1 mass ratio impact. We solve a two-body problem for this interaction and find that the most likely solution suggests that the merging axis lies almost contained in the plane of the sky and the subcluster will fully interact in $\sim0.3$ Gyr. The comparison between the dynamical masses and those derived from X-ray data reveals a good agreement within errors (differences $\sim 15$\%), which suggests that the innermost regions ($<r_{500}$) of the galaxy clumps are almost in hydrostatical equilibrium. To summarize, RXCJ1230 is a young but also massive cluster in a pre-merging phase accreeting other galaxy systems from its environment.
